WSJ.com: Deadly Australian Spider Spins Web Across Japan

A poisonous spider from Australia is spinning its web across Japan, with sightings of the pesky arachnid increasing to about half of the country’s prefectures.

On Wednesday, the environment ministry warned the public to be on the lookout for the redback spider, which has been spotted in 23 of the country’s 47 prefectures. The creepy crawler has been invading Japan in growing numbers since one hitched a ride on a shipping container from Australia in 1995.

The redback spider, distinguished by the fireball marking on its black back, has become a seasonal pest in big port regions in western Japan like Osaka and Fukuoka. But the ministry said the migratory spider has become more ambitious, reaching farther into Japan, from Miyagi prefecture in the chilly northeast to the beaches of Okinawa in the southwest.

Smaller than a thumb tack, the redback injects a potent neurotoxin when it clamps down on a victim’s skin. Victims could suffer from nausea, headaches, heavy perspiration and chest pains. An anti-venom discovered in 1956 has helped cut fatalities from the spider’s lethal bite, and so far no deaths have been recorded in Japan. However, anti-venom had to be administered to an 86-year-old woman in Fukuoka in early September, after she was bitten by a redback hiding in her shoe.There have been over 100 sightings of the spider in Fukuoka city so far this year.

The redback has been recorded in 18 prefectures until now, according to the National Institute for Environmental Studies. It is also creeping closer to Tokyo. The industrial city of Kawasaki, located in neighboring Kanagawa prefecture, had its first sighting ever on Monday. The city raised an alert after one spider and three eggs were discovered in a private home on Monday.

Authorities have warned the public not to touch the spider, which is relatively passive when left alone and can be killed with pesticide. Redbacks thrive in warm temperatures and tend to pop up from June to October, but the spiders have been found to be hanging about longer in recent years, taking refuge near heat-emitting appliances like vending machines.